In conventional photography, the camera must typically be focused at the time the photograph is taken. The resulting image may have only color data for each pixel; accordingly, any object that was not in focus when the photograph was taken cannot be brought into sharper focus because the necessary data does not reside in the image.
By contrast, light field images typically encode additional data for each pixel related to the trajectory of light rays incident to that pixel when the light field image was taken. This data can be used to manipulate the light field image through the use of a wide variety of rendering techniques that are not possible to perform with a conventional photograph. In some implementations, a light field image may be refocused and/or altered to simulate a change in the center of perspective (CoP) of the camera that received the image. Further, a light field image may be used to generate an enhanced depth-of-field (EDOF) image in which all parts of the image are in focus.
Unfortunately, the resulting EDOF image may have undesirable effects that appear out-of-place to a viewer. Some such effects may occur as a result of image degradation that occurs during the image capture process, such as blurring due to focusing or noise. Further, these effects may include artifacts caused by the image processing used. More particularly, image processing performed on EDOF images can create unwanted artifacts because the depth map accuracy as well as the light field data itself can have strong depth-dependent variation in terms of sampling, prefiltering, and noise level. Different processing parameters may be appropriate for different depths, making it difficult to parallelize processing flow. Furthermore, mismatches in parameters between nearby regions of different depths can yield visible (and unwanted) discontinuities in the processed image.
It would be an advancement in the art to provide processing systems and methods capable of preventing, removing, and/or mitigating such effects.